Methods and Uncertainties

Methods used in the radial-velocity program of short-period binary systems at the David Dunlap Observatory are described with particular stress on the Broadening Function (BF) formalism. This formalism has permitted determination of radial velocities from complex spectra of multiple-component systems with component stars showing very different degree of rotational line broadening. The statistics of random errors of orbital parameters is discussed on the basis of the available orbital solutions presented in the six previous papers of the series, each with ten orbits. The difficult matter of systematic uncertainties in orbital parameters is illustrated for one typical case of GM Dra from the most recent Paper VI. Subject headings: stars: close binaries stars: eclipsing binaries – stars: variable stars